ISC Steel Arborist Posi Double-Locking Carabiner
Robust ISC Steel Arborist Posi (Big Dan Supersafe) carabiner, rated 50 kN with a 1 in gate opening and double‑locking 3‑way gate, manufactured in Great Britain for demanding tree work systems.
The ISC Steel Arborist Posi Carabiner Double‑Locking uses the proven KH455 Big Dan steel body, giving you a very strong connector for climbing and rigging in arborist and rope access work. With a 50 kN minimum breaking strength and approximately 27 mm (about 1–1 1/8 in) gate opening, it handles large ropes, slings, and hardware clusters while maintaining an excellent strength‑to‑size ratio. The Supersafe (Posi) 3‑way gate requires three deliberate actions to open, greatly reducing the chance of accidental gate opening in service.
Forged from heat‑treated steel and zinc‑plated for corrosion resistance, the Big Dan’s modified‑D shape helps keep loads correctly aligned along the major axis and minimizes snagging with its blind nose profile. Manufactured in Great Britain and certified to EN 362, it is a solid choice for primary climbing attachments, belay or rescue anchors, and high‑wear connection points where aluminum hardware might fatigue or deform more quickly.
- 50 kN steel construction: Forged steel body with a minimum breaking strength of 50 kN (about 11,240 lb) for life‑support and heavy rigging applications.
- 1 in / 27 mm gate opening: Large gate clearance makes it easy to clip over thick ropes, slings, and multiple connection points without fighting the hardware.
- Supersafe double‑locking gate: ISC 3‑way “Supersafe” / Posi gate requires lift‑twist‑open action and auto‑locks closed to guard against accidental opening.
- Ergonomic Big Dan shape: Large modified‑D profile with blind nose helps prevent snagging and keeps loads oriented on the major axis for optimal strength.
- Durable zinc‑plated finish: Zinc plating over steel provides good wear and corrosion resistance for long‑term outdoor arborist use.
- Made in Great Britain: Manufacturer part number KH455SS1.2, produced by ISC Wales and CE‑marked to EN 362 industrial connector standards.





























